For an Orthogonal Frequency Division Multiple Access (OFDMA) access mode adopted by a conventional Long Term Evolution (LTE) system designed on the basis of orthogonal transmission, it is able to perform data transmission and reception conveniently, and ensure the system performance. However, along with the rapid development of mobile Internet business and Internet of Things (IoT) business applications, a non-orthogonal multiple access technology has shown more advantages in terms of system capacity, time delay and the number of terminals supported thereby, so it may probably be adopted by a fifth Generation (5G) mobile communication system. For the non-orthogonal multiple access technology, information about different users is transmitted through an identical transmission resource, and interference is introduced artificially, so it is necessary to cancel the interference at a receiving end through a more complex receiver algorithm. Currently, some typical non-orthogonal multiple access technologies include Non-Orthogonal Multiple Access (NOMA), Sparse Code Multiple Access (SCMA) and Pattern Division Multiple Access (PDMA).
For the NOMA, multi-user signals are superimposed at a power domain, and a Serial Interference Cancellation (SIC) receiver is adopted at the receiving end. For the SCMA, as a novel frequency-domain non-orthogonal multiple access technology, different data streams are mapped to different codewords in a multi-dimensional codebook, each codeword represents an extended transport layer, and all the SCMA transport layers share an identical time-frequency resource block. At the receiving end, a decoding operation may be performed using an iterative Message Passing Algorithm (MPA) on the basis of sparsity of the codewords, so the SCMA has performance very close to optimal detection. For the PDMA, at a transmitting end, the users are differentiated from each other in accordance with non-orthogonal characteristic patterns of a signal from a terminal based on a plurality of signal domains such as the power domain, a code domain and a spatial domain using a pattern division technique, and at the receiving end, multi-user detection may be performed using a Belief Propagation (BP) algorithm receiver and the SCI receiver on the basis of a characteristic structure of a terminal pattern, so as to provide the system capacity approaching to a capacity boundary of a multiple access channel.
Currently, for the PDMA technology, an encoding matrix may be used as a basic mapping pattern so as to differentiate the users from each other. Usually, each row of the encoding matrix corresponds to a frequency-domain resource block which participates in data mapping for multi-user multiplexing, and each row represents a multi-user data pattern mapping mode. For example, in the case that N frequency-domain transmission resources are multiplexed by M users in a superposition encoding manner, a theoretical maximum value of M may be 2N−1, depending on a principle where the M users can be differentiated from each other in terms of their encoding modes. At this time, a theoretical multi-user superposition encoding matrix (i.e., HPDMA) formed through the multi-user superposition encoding may be expressed as the following equation:
                                          H            PDMA                          (                              N                ,                M                            )                                =                                    [                                                                    1                                                        1                                                        …                                                        0                                                                                                                                                          1                                                        …                                                        0                                                                                        1                                                        1                                                                                                                                                          0                                                        …                                                        0                                                                                                                                                          0                                                                                        ⋮                                                        ⋮                                                        ⋱                                                        ⋮                                                        …                                                        ⋮                                                        ⋱                                                        ⋮                                                                                        1                                                        0                                                        …                                                        1                                                                                                                                                          0                                                        …                                                        1                                                              ]                                      N              ×              M                                      ⁢                                  ⁢                                                                                                                                                                          diversity                          ⁢                                                                                                          ⁢                          order                                                =                        N                                                                                                                                                C                        N                        N                                                                                                                                                                                                                                      diversity                          ⁢                                                                                                          ⁢                          order                                                =                                                  N                          -                          1                                                                                                                                                                        C                        N                                                  N                          -                          1                                                                                                                                                                                                                                                              diversity                          ⁢                                                                                                          ⁢                          order                                                =                        1                                                                                                                                                C                        N                        1                                                                                                                          .                                    (        1        )            
For the conventional PDMA technology, with respect to the actual implementation capability of the system, an appropriate construction scheme of the PDMA encoding matrix may be determined, so as to make a compromise between the system capacity and the calculation complexity. However, in the related art, a pattern mapping mode between the multi-user data and the encoding matrix is inflexible, and in the finally-determined encoding matrix, usually the data for one user is merely mapped to a certain column of the encoding matrix. Hence, in the case that a small amount of users are scheduled by the system, it is impossible to increase a transmission load of a User Equipment (UE), and thereby a throughput of the system may be limited.